The present invention relates to a printer and image processing apparatus, image processing method and image processing program.
Conventionally, as the data record format of an image input apparatus such as a digital camera, there is known a RAW format in which the pixel data of a color image sensor are digitally recorded as they are (see Japanese Patent Publication No. 2005-33468). Since the color image sensor normally carries thereon color filters respectively for R (Red), G (Green) and B (Blue) for each pixel, the RAW data having only one color component for each pixel are incomplete information as an image representing an object to be printed. Therefore, until a demosaicing processing (which is also referred to as a color falter arrangement interpolation processing), in which at least a color component lacking in each pixel is estimated and interpolated by the color component of a neighboring pixel to thereby generate a color image having three color components for each pixel, are enforced on the RAW data, an image representing the object cannot be printed. In a printer the manufacturing and developing costs of which are restricted severely, there has been urgently needed the development of a technology for printing an image using an RAW data file.
Meanwhile, image processing apparatus, which handle RAW data, has an image generating function which depends on the models of individual digital cameras and uses at least a demosaicing processing, and a function for correcting an image generated by the demosaicing processing. In this type of image processing apparatus, in some cases, there are executed similar processings in a preceding stage up to generation of an image and in a correcting stage after generation of the image. For example, in the preceding stage up to generation of the image, there is executed a sharpness correcting processing for recovering the lowered sharpness due to a low pass filter provided in a digital camera; and in the correcting stage after generation of the image, there are executed a sharpness correcting processing for glossing over the setting errors of focus, stop and shutter speed as well as a sharpness correcting processing according to the print resolution. When these image processings, the objects of which are different but to which the same algorithm for correction is applied, can be executed collectively, the processing time can be shortened. Also, because the image processing essentially involves the deterioration of information, by reducing the number of times the image processings are executed, there is a possibility that the quality of the image can be improved. Further, when a pixel interpolation processing for enhancing the resolution is carried out after execution of a sharpness correcting processing, there is raised a problem that jaggies can appear clearly. Therefore, it is desirable that such sharpness correcting processing prior to execution of the pixel interpolation can be avoided.